Added Keyword model. (#3)
Added test for adding a stream to a keyword and fixed typos. (#3)
Added test for default keyword type and fixed set_keyword method. (#3)
Added test for set keyword type and fixed set_key_type method. (#3)
Added test for set keyword. (#3)
Merge pull request #6 from tiriplicamihai/f/#3-keyword-table-branch

F/#3 keyword table branch